Integrating Space Traffic into the National
Airspace System

Story and photos by Victoria A. Brown
Reprinted with permission from FAA Aviation News

Picture a world where spacecraft and
aircraft share the same airspace from take-off to re-entry
to landing, and where airplanes do not have to be grounded
because spacecraft need to use the airspace. In this world,
air traffic controllers will control air and space traffic
together. Soon you no longer have to daydream what it would
be like, because a system that can help to make this all
possible is now being developed.

With the anticipated increase in air traffic
and spacecraft operations, the Federal Aviation
Administration (FAA) expects greater demands on the National
Airspace System (NAS) and the nation's Air Traffic Control
(ATC) system over the next 10 years. To handle this influx
in traffic, the FAA has developed a concept of operations
for a future Space and Air Traffic Management System
(SATMS). SATMS represents a framework for "seamlessly
integrating" space vehicles on their way to and from space
with more traditional air traffic operations. Of course,
this will entail new space and air traffic management tools
along with improved communications, navigation, and
surveillance services.

There are unique hazards involving space
flights. If a space vehicle should fail in a manner that
generates debris, as occurred with the space shuttle
Columbia accident, it could pose a grave threat to aircraft
flying below. A piece of spacecraft debris weighing less
than one pound could puncture the wing or cabin of a
cruising aircraft causing catastrophic damage. Since
potential hazards from spacecraft operations pose far
greater risks than any other aircraft hazard traditionally
considered, SATMS would need to address these issues to make
the NAS even safer than it is today.

Currently, there are several strategies used
to manage air traffic. The Notice to Airmen (NOTAMs) method
alerts the aviation community, including air traffic
controllers, airlines, and general aviation pilots of the
times of space flight operations and boundaries of the
required airspace. The airspace restrictions are enforced by
Title 14 Code of Federal Regulations (14 CFR) part 91.
Special Use Airspace (SUA) establishes Restricted Areas and
Warning Areas. Restricted Areas are established with fixed
boundaries and are illegal to enter without permission from
the controlling agency. Altitudes and times of activation
differ. Warning Areas are airspace over domestic or
international waters that extend from three nautical miles
outward from the coast of the United States. Warning Areas
are advisory in nature to alert pilots that they may be
entering areas of hazardous activity to nonparticipating
pilots. Lastly, air traffic controllers have the option to
issue a Temporary Flight Restriction (TFR). This is a
short-term restriction to keep aircraft from entering
certain areas. TFRs are often issued on very short notice
for a variety of reasons. The airspace is sized for the
largest vehicles that may use it with fixed boundaries and
are typically activated for extended periods of time. These
methods also impact space vehicle operators because they
require extensive advanced coordination with various ATC
entities, and it is sometimes difficult to accommodate
launch delays and scrubs.

In the future, FAA hopes to reduce the
amount of airspace that is restricted for each launch and
the amount of time that the restriction needs to be in
effect. FAA also hopes to schedule the restrictions to
accommodate conventional air traffic while still achieving
the safety and space mission objectives. One of the ways FAA
plans to achieve this is through space transition corridors.
A space transition corridor is a strategically sized
airspace restriction. Its vertical extent spans all
altitudes and the lateral sizing will be determined by using
specific characteristics of vehicle operations and predicted
weather conditions. It will be dynamically issued and
withdrawn to minimize impact to air traffic.

In the case of an accident, the SATMS
Decision Support Tool (SATMS DST) will ultimately assist air
traffic controllers in managing airspace and the risk to
aircraft from space operations with improved situational
awareness. Air traffic controllers will be able to better
predict airspace affected by debris. This tool will also
identify and plan the most efficient air traffic reroutes as
well as track the spacecraft, or in the worse case scenario,
its debris through the NAS.

Needless to say, there is a lot of planning
and analyzing that goes into developing this system. Before
the space shuttle Columbia accident, FAA air traffic
procedures for supporting space shuttle operations did not
take into consideration the potential debris hazard to
aircraft during a shuttle reentry. For this reason, the
Shuttle Recovery Ops Team was formed. The team consists of
participants from the National Aeronautics and Space
Administration's (NASA) Johnson Space Center and FAA's
Office of Commercial Space Transportation, Air Traffic
Control System Command Center, William J. Hughes Technical
Center, Albuquerque Air Route Traffic Control Center
(ARTCC), Houston ARTCC, Jacksonville ARTCC, Los Angeles
ARTCC, Miami ARTCC, and Oakland ARTCC. Until the SATMS DST
is fully developed and functional, the Shuttle Recovery Ops
Team runs shuttle reentry exercises to train and prepare air
traffic controllers for possible accidents like Columbia.
These exercises simulate what could happen in the event of a
space shuttle accident. On the last re-entry exercise the
"shuttle debris" entered over Los Angeles ARTCC's airspace.
In the exercise, Oakland and Albuquerque ARTCCs assisted Los
Angeles in moving potentially at risk aircraft away from
harm. After the exercise was completed, all parties agreed
that this training was indeed beneficial.

The SATMS Decision Support Tool would
automate the processes involved. Ultimately the goal is for
the SATMS DST to compile all the information from any given
accident or launch and re-entry vehicle operation and
translate that data into a real-time tool that ATC would use
to manage the traffic situation.

FAA is working with NASA to ensure that the
skies stay as safe as possible during space launches.
Furthermore, both organizations are practicing to become as
proficient as possible. With the expected air traffic
increase and the development of commercial space flights,
SATMS DST provides an important means to manage the expected
workload.

Victoria Brown was an FAA summer intern. She
is a communications major at Xavier University in
Cincinnati, Ohio.